I always use an aggressive M+S tread on my truck, all 6 positions. I have noticed no handling problems when towing the fifth wheel, or when loaded with 35 bales of hay on the truck, while towing the flatbed trailer with 100 bales on it.
I also have Cooper Discoverer M+S tires on the Tioga, all 6 positions. No handling problems noticed, whether towing the Jeep or not. The Jeeps, of course, have very aggressive M+S tires on them.
Get the tread pattern that will give you the traction you want and need.

As for comparing the Big O and Wild Country tires, I have no idea why the price difference. It could be just the dealer.

Finally decided to go with Cooper Discovery AT3 tires. They are about $200 each but they will last 55K miles and look like a lot better tires than Wild Country. Thanks for your input and happy camping.

I'd be interested to hear how the hold up. I have had the XTX's (285/70R17) on my Dodge for over 26K miles now and I think they are wearing pretty good. I run the fronts at 65 psi and rears at 45 psi empty or 60 psi when towing. After 26K miles tread is down to 10/32's (started @ 15/32's) all around and wearing very evenly with rotations every 5-8K miles.

Overall I've been happy with the XTX's. Quiet, comfortable and appear to be wearing well for an AT.